Two-stage drop hammer for driving large diameter piling

ABSTRACT

A two-stage or multi-stage drop hammer for driving large diameter piling having a backing plate welded onto the upper terminal end of a cylinder to be driven to form a pile, a hammer guide secured onto the backing plate, said hammer guide containing an annular, contoured first hammer for impacting upon a large peripheral portion of the bottom member of the hammer guide, and a second hammer for impacting upon a large central area of the bottom member of the hammer guide, and a flanged extension on the second hammer for lifting the first hammer to a distance above the bottom member of the hammer guide, whereupon dropping of the hammers provides and allows the first hammer to impact upon the bottom member of the hammer guide in timed sequence ahead of the second hammer impacting upon the bottom member of the hammer guide.

United States Patent Evans Oct. 24, 1972 [54] TWO-STAGE DROP HAMMER FORDRIVING LARGE DIAMETER PILING [72] Inventor: Robert G. Evans, P.O.Drawer 68, Harvey, La. 70058 [22] Filed: March 8,1971 [21] Appl. No.:121,663

[52] US. Cl ..173/l03 Primary Examiner-James A. LeppinkAttorney-Misegades & Douglas [57] ABSTRACT A two-stage or multi-stagedrop hammer for driving large diameter piling havinga backing platewelded onto the upper terminal end of a cylinder to be driven to form apile, a hammer guide secured onto the backing plate, said hammer guidecontaining an annular, contoured first hammer for impacting upon a largeperipheral portion of the bottom member of the hammer guide, and asecond hammer for impacting upon a large central area of the bottommember of the hammer guide, and a flanged extension on the second hammerfor lifting the first hammer to a distance above the bottom member ofthe hammer guide, whereupon dropping of the hammers provides and allowsthe first hammer to impact upon the bottom member of the hammer guide intimed sequence ahead of the second hammer impacting upon the bottommember of the hammer guide.

6 Claims, 2 Drawing Figures mmenomwm 0.700.046

v k v ROBERT 0. EVANS r 7 0 W'd fidfl ggg ATTORNEYS I4 I I I4 TWO-STAGEDROP HAMMER FOR DRIVING LARGE DIAMETER PILING BACKGROUND OF THEINVENTION The present invention relates to drop hammers for drivingunusually large diameter piling, and more particularly relates to thearrangement of hammers for driving metal cylindrical piling having up toeight feet diameter or more, and being essentially unique in that thereare twoor multi-stage hammers which impact or strike the pilinginitially with a reduced amount of energy, then following almostinstantaneously in time with an increased amount of energy in the formof mechanical forces.

Generally speaking, there are at least two types of hammers in existencefor driving pilings into river bottoms, and the like, one of which is adrop hammer which functions and operates on the principle of a weightbeing lifted and then dropped onto the piling, driving it into theground; and the other type being mechanical in which the hammer isactuated at an essentially faster rate of impact such as by air, steam,or by mechanical vibrations or rapid rates. While the drop hammer is asimpler form, it is generally slower and if it is made sufficientlymassive to acquire additional speed by driving the piling further witheach blow, there is a risk of fracturing the piling.

BRIEF SUMMARY OF THE INVENTION lt is an object of the present invention,therefore, to provide means for reducing and eliminating all risk offracturing the piling, and to provide improved piling as well asattaining the result of more quickly installing the pile driving intoriver beds and other ground, and the like.

A further object and advantage of the present invention is to provide atwo-stage or multi-stage drop hammer, it having a number of advantagesand improvements over conventional single-stage drop hammers, such asthe following 1. The lifting mechanism lifts the second stage which islighter first, and gets it moving before the second stage is engaged,reducing the shock on the lifting mechanism;

2. The chance of fracturing the piling is reduced since the first stagehammer engages the piling with less energy momentarily before the secondstage is engaged. Since the first stage starts the piling moving, it isable to absorb more energy when the second stage hammer engages it, dueto a reduction in inertia, which is occasioned by the piling being inmotion when struck by the second stage hammer;

3. The cost of the drop hammer is considerably less than a mechanicalhammer producing the same amount of energy;

4. Maintenance and operating skill would be considerably less; and

5. The design lends itself particularly well to driving large diametercylinders.

It is a further object and advantage of the present invention to apply alighter force to initiate the movement of the piling, followed almostinstantaneously in time by a greater impact force. Where more than twostages are designed into the multi-stage unit, these forces wouldincrease progressively at each additional stage of impact. However, itis not found at present to be practical to visualize a hammer of thisinvention having more than five stages.

The above and other objects and advantages of the invention will becomeapparent upon full consideration of the following detailed descriptionand accompanying drawings in which:

FIG. 1 shows a side elevation view shown in part cross-section of atwoor multi-stage hammer according to a preferred embodiment of thepresent invention for driving large diameter piling and the like; and

FIG. 2 shows a detailed enlarged view of the cable connection for thelever means for lifting the first stage hammer by a flanged extension ofthe second stage hammer.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings,there is shown a cylinder 10 of essentially large diameter, the cylinderforming the piling to be driven, and which may be filled with concreteor other material filling, if desired. The upper end of the cylinder 10terminates in a back member or impact member such as a backing plate 12that is welded to the top edge of the cylinder 10.

There is secured upon the top surface of the backing plate 12 a bottommember 16 of a hammer guide 18, the hammer guide having a generallycylindrical configuration with said bottom member 16. On a largeperipheral area of the bottom member is an annular plate 22 disposed forreceiving the application of a large mechanical force, and centrallydisposed thereof on the bottom member 16 is a central means 24 forming alarge central area for receiving also the application of a largemechanical force.

Within the hammer guide 18, there is a first'hamm er 26 having a hollowcentral portion and which traverses a portion of the entire length ofthe hammer guide. When the first hammer 26 is dropped upon the platemember 22, a large impact applies a mechanical force to the largeperipheral area of the bottom member which is transferred to thecylinder 10 for driving it downwardly.

A second hammer 28 central of the first hammer 26 traverses the entirelength of the hammer guide 18 and upon impact it applies a largemechanical force to the large central member 24, which is transferredalso to the cylinder 10. The hammer guide has a top member 30 whichextends upwardly from the cylindrical element of the hammer guide andthe top member includes a cable guide 34 extending upwardly therefrom.On the top of the second hammer 28, there is a cable coupling 32 andcable means 33, 33 passes through the cable guide 34 and is coupled tothe upper terminal end of the first hammer 26 at a coupling means 36.The slack in the cabling means is adjustable in length so that, asdescribed below, the first hammer may be lifted by the cable means priorto it being lifted by a flanged extension 40.

The second hammer 28 is provided with the flanged extension 40throughout the entire peripheral element at the impact end of the secondhammer. The second hammer 28 is provided with an internal tubular guide42 for allowing passage of the second hammer together with its flangedextension 40. The upper end of the first hammer 26 and the tubular guide42 is provided with a plurality of pivotally mounted, radially disposedlevers 46, 46 having their outer ends engaging a spring 48, 48,respectively, which spring biases the other end of the lever generallyupwardly and thus the air ends are prone to be biased downwardly as aresult of the force due to the spring 48. The lever is pivotallysupported by means 50, as shown.

When the second hammer 28 with its flanged extension 40 reaches theupper position within the tubular guide, it engages the inner ends ofthe radially disposed levers 46, 46 and together with the tautness ofthe cabling means 38, the first hammer 26 and the second hammer 28 arethen lifted until the first hammer reaches the upper end of the hammerguide 18.

The first hammer 26 may be of a weight such as 36,000 pounds, droppedthrough a distance of 3 feet, and provides a force of 108,000 pounds.The second hammer 28 may be of a weight, for example, of 17,000 poundsand if dropped through a distance of, for example, feet, provides aforce equal to 170,000 foot pounds. This force is applied to thecylinder 10 to be driven in forming a piling according to the presentinvention.

When the terminal coupling 60 at the upper end of the second hammer 28is raised, such as by a cable connected to a crane or the like, thesecond stage is lifted the entire length of the hammer guide 18 and theflanged extension 40 at the impact end of the second hammer engages withthe inner lever ends 50 of levers 46, 46, any abruptness of such forcebeing absorbed by the spring means 48, 48, so that the first hammer 26is raised until the levers 46, 46 reach or engage with the top hammer30. The first hammer is supported by the flanged extension 40 of thesecond hammer 28 when the flanged extension travels the full distance topivot support means 50. When the first and second hammers are broughtinto engagement with plate members 22, 24, respectively, the cabling(not shown) connected to the coupling 60 is momentarily released so thateach of the second (or first) hammer drops. The first hammer 26 dropsonly, for example, three feet through the hammer guide which may begenerally 10 feet in height and engages the peripheral member 22, theimpact being first transferred to the cylinder 10. This is a lighterforce than the force of the second hammer and starts the piling moving.There is followed almost instantaneously the greater force of the secondhammer which falls through the distance of 10 feet, that is, the entiredistance, for example, of the hammer guide, and its force is applied tothe plate 24, which force is trans ferred to the backing plate 12similarly to the force of the first hammer to the cylinder 10. Thesequential applicationof these forces in increased progressively rangesof magnitude of forces at each additional stage provide greaterlongitudinal movement of the piling formed by cylinder 10 than isaccomplished by separate applications of the hammer, according to priorart means and methods.

The plate 24 within the hammer guide 18 may be coupled by bolts 70, 72to the backing plate 12, which are as shown in FIG. 1. By meanstherefore, the present invention provides a multi-stage hammer to drivemetal cylindrical piling which may be up to eight feet in diameter byimproved methods into river bottoms, ground, and other areas, so thatthe staged hammer application of forces for driving the pilings with areduced amount of energy, then followed almost instantaneously with anincreased amount of energy, provides faster, more efficient and improvedinstallation of pilings. In FIG. 2, there is shown the manner by whichcabling means is provided to a coupling 76 and a bolt 78 for lifting thefirst hammer 26 by coupling the bolt 78 to a upper end of the tube 42.There is also shown the manner in which the lever 46 is pivotallycoupled by a pivot means 50 to the first hammer 26.

When a shorter interval between the impacts of the first and secondhammers is desired, adjustment of the length of the cabling means 33 ismade and calculated so that the second hammer falls and impacts at ashortened predetermined time after the fall and impact of the firsthammer. Thus, the cabling means 33, 33 is used only when second hammer28 is less than full drop on capacity. This allows and permits thesecond hammer 28 to start lifting the first hammer 26 at any selectedpredetermined point in time that is less than the point of engagement.

Additional embodiments of the invention in this specification will occurto others and, therefore, it is intended that the true spirit of theinvention be limited only by the appended claims and not by theembodiments described hereinabove. Accordingly, reference should be madeto the following claims in determining the true spirit of the invention.

What is claimed is:

1. A twoor multi-stage drop hammer for driving large diameter piling andthe like comprising:

a large diameter cylinder to be driven to form a pile, having its upperend terminating in a backing plate welded onto the cylinder,

a hammer guide having a bottom member secured by means onto the backingplate having a large peripheral area for' receiving the application of amechanical force and a large central area for receiving also theapplication of mechanical force,

said hammer guide having a generally cylindrical configuration with saidbottom member,

a first hammer for traversing a portion of the entire length of thehammer guide and upon impact applying a mechanical force to said largeperipheral area of said bottom member,

a second hammer for traversing the entire length of the hammer guide andupon impact applying said mechanical force to said large central area ofsaid bottom member, and

said hammer guide having a top member and including a cable guideextending upwardly thereof.

2. The invention according to claim 1 wherein said cabling means passesthrough said cable guide coupled at each end, one to the upper terminalend portion of the first hammer and the other to the upper terminal endportion of the first hammer.

3. The invention according to claim 1 wherein said first mentioned meansin the hammer guide are bolts securing it to the backing plate.

4. The invention according to claim 1 where the cabling means isadjustable in length so that the first hammer is lifted up by thecabling means prior to the lower end of the second hammer traverses theentire vertical length of the hammer guide.

5. The invention according to claim 1 wherein a tubular guide isdisposed within the first hammer for the outer ends spring-biasedupwardly and the inner ends acting against the spring-biased action whenthe second hammer reaches the upper position on the said hammer guide byengaging said levers with said flanged extension of said second hammer.

1. A two- or multi-stage drop hammer for driving large diameter pilingand the like comprising: a large diameter cylinder to be driven to forma pile, having its upper end terminating in a backing plate welded ontothe cylinder, a hammer guide having a bottom member secured by meansonto the backing plate having a large peripheral area for receiving theapplication of a mechanical force and a large central area for receivingalso the application of mechanical force, said hammer guide having agenerally cylindrical configuration with said bottom member, a firsthammer for traversing a portion of the entire length of the hammer guideand upon impact applying a mechanical force to said large peripheralarea of said bottom member, a second hammer for traversing the entirelength of the hammer guide and upon impact applying said mechanicalforce to said large central area of said bottom member, and said hammerguide having a top member and including a cable guide extending upwardlythereof.
 2. The invention according to claim 1 wherein said cablingmeans passes through said cable guide coupled at each end, one to theupper terminal end portion of the first hammer and the other to theupper terminal end portion of the first hammer.
 3. The inventionaccording to claim 1 wherein said first mentioned means in the hammerguide are bolts securing it to the backing plate.
 4. The inventionaccording to claim 1 where the cabling means is adjustable in length sothat the first hammer is lifted up by the cabling means prior to thelower end of the second hammer traverses the entire vertical length ofthe hammer guide.
 5. The invention according to claim 1 wherein atubular guide is disposed within the first hammer for passagetherethrough of the second hammer, and said second hammer has a flangedextension at the impact end thereof.
 6. The invention according to claim4 wherein said tubular guide at the upper end terminates in a pluralityof pivotally mounted, radially disposed levers having the outer endsspring-biased upwardly and the inner ends acting against thespring-biased action when the second hammer reaches the upper positionon the said hammer guide by engaging said levers with said flangedextension of said second hammer.